The UK-wide survey from the National Autistic Society of Northern Ireland reported that 50% of both autistic people and family members often don't leave the house because of fears of how people will react to autism.

More than one in 100 people are on the autism spectrum, with many often finding social situations difficult.

They struggle to filter out the sounds, smells, sights and information they experience, meaning they feel overwhelmed by "too much information" when out in public.

The charity's research showed that this lack of understanding means autistic people and families often face tutting and judgmental stares by others.

Over time it means they avoid going to places they might feel overwhelmed or judged, and become more and more isolated.

Mark and Cathy Mulholland are the parents of 10-year-old Malachy, who has a severe learning disability, and have witnessed him being taunted by adults in public.

"I would say to these people and others who stare and make fun of Malachy when we are out that my son and his family have enough on their plate trying to access suitable activities and giving him enjoyable experiences without having to endure imitations of a child with special needs who is doing nothing but trying to enjoy life," Mark said.

"The fact is that Malachy needs to be out and about. He needs to experience activities which he enjoys. We attempt as far as possible to shield our son and ourselves from negative attitudes displayed by some members of the public. However, his happiness is more important to our family than any of their opinions and judgments, and we will continue to bring him out."

The Belfast couple were speaking as the National Autistic Society launched the Too Much Information awareness campaign. Its aim is to increase public understanding of autism, so people can respond with empathy.

"However, being Malachy's parent is rewarding and we love our son dearly," said Mark. "He is entitled to the same happiness and fun that all children are.

"It is just that much more thought, effort and attention has to go into identifying where and when we can go to places so Malachy can enjoy himself - but also so we do not have to experience the added pressure of judgment by members of the public."

Shirelle Stewart, director of the National Autistic Society Northern Ireland, said: "It isn't that the public sets out to be judgmental towards autistic people.

"They tell us that they want to be understanding but often just don't 'see' the autism. They see a 'strange' man pacing back and forth, or a 'naughty' girl having a tantrum on a bus, and don't know how to respond.

"Autism is complex and autistic people and their families don't expect or want people to be experts. But our research shows that when people recognise that someone is autistic, and understand the difficulties they face, they're more likely to respond with empathy and understanding.

"A basic understanding could transform the lives of the more than one in 100 autistic people in Northern Ireland and their families."